1. Field of the Invention
The present invention relates to a retaining center of a compact disc (CD) box and in particular, a retaining center which can securely retain a DVD/VCD/CD without fracture and which allows easy insertion and removal from the DVD/VCD/CD box.
2. Background
Compact discs have become an indispensable medium for storage of information, whether as music or text, etc. Such discs are commonly stored in plastic boxes when not in use to protect the surfaces of the discs despite them generally being impervious to reduced information playback through scratching, dust, finger marks, etc. The boxes generally have a resilient center onto which the disc is secured by means of a central hole in the disc. The central hole has a diameter slightly smaller than a diameter of the center in an extended condition.
FIGS. 7 and 8 show a first example of a prior art resilient center for a DVD/VCD/CD box, wherein the center is formed protruding from a base plate of the box. The center includes an outer ring (61) and an upright boss extending integrally from the ring (61). The boss comprises a plurality of equi-spaced ribs separated by a corresponding plurality of equi-spaced slits (62) which all communicate with a central opening. To fit a DVD/VCD/CD to such a box, the central hole of the DVD/VCD/CD is aligned with an outer periphery of the boss and then pressure via a user's finger tips is put on the top of the DVD/VCD/CD, whereby the ribs are temporarily deformed inwards to the central opening of the boss. When pressure from the user's finger tips is released, the ribs spring back outward a little due to resilience caused by the slits (62) and the DVD/VCD/CD is gripped by tension in the ribs. To release the DVD/VCD/CD from the box, the user has to press down a top of the boss whereby the ribs are forced inward again towards the center of the boss, until a diameter across the ribs is smaller than the diameter of the central hole of the DVD/VCD/CD, and then the DVD/VCD/CD can be removed. Although such a box works quite well in a crude way, it is found that the ribs often fracture, especially after repeated removal and insertion of the DVD/VCD/CD, and then the DVD/VCD/CD is no longer reliably retained in the box.
A second prior art DVD/VCD/CD box (70) with a resilient center is shown in FIG. 9, wherein a mount (71) includes two symmetrical inclined portions (72) each with a lower end integrally formed with a base plate, and an upper distal end formed with a substantially semi-circular boss (73). The semi-circular periphery of each boss (73) has a lip (74) formed on a top edge thereof. A face opposite each semi-circular periphery is curved such that an "S" shaped slit is defined between the two bosses (73). A diameter across the bosses (73) is slightly smaller than the diameter of the central hole of the DVD/VCD/CD, and a distance across the lips (74) is slightly smaller than the diameter of the central hole of the DVD/VCD/CD.
In use, the central hole of the DVD/VCD/CD is aligned with the bosses (73) and then the DVD/VCD/CD is pushed down such that the inclined portions (72) are also pushed down whereby the bosses (73) move towards each other and narrow the width of the slit, and thus the distance across the lips (74) is now smaller than the diameter of the central hole of the DVD/VCD/CD. Thus the DVD/VCD/CD can be secured on the bosses (73) and below the lips (74). Once pressure from the finger tips of the user is released, resiliency of the inclined portions (72) urges the bosses (73) outward, such that the lips (74) return to have the distance thereacross greater than the central diameter of the DVD/VCD/CD. A reversal of the aforementioned process enables a user to release the DVD/VCD/CD from the box. There are three drawbacks found with this second prior art DVD/VCD/CD box:
1. difficulty is often experienced by users in locating the central hole of the DVD/VCD/CD over the bosses (73); PA1 2. it is found that the retention of the bosses is not reliable, and so users do not have complete confidence in such a box; and PA1 3. it is difficult to line up the DVD/VCD/CD in a flat way parallel to the box, and so the DVD/VCD/CD is often stored askew which overstresses the retainer and ultimately leads to failure thereof.
Thus, there is a long and unfulfilled need for a retaining center for a DVD/VCD/CD box which does not fracture, and which can accurately and reliably receive a DVD/VCD/CD thereon.